Ischemic stroke is the third leading cause of death and disability in the industrialized world. Known systems perform magnetic resonance imaging (MRI) scans on a patient suffering from ischemic stroke to identify the degree of mismatch between volumes of dead and ischemic tissue using diffusion-weighted and perfusion-weighted MR images, respectively. The so-called ischemic penumbra is an important marker used to triage patients for endovascular therapy. Perfusion-diffusion mismatch is poorly standardized among imaging facilities, causing variability when used for stroke diagnosis. However, known systems lack capability to automatically evaluate the degree of perfusion-diffusion mismatch between MR images and additionally need to acquire perfusion-weighted and diffusion-weighted MR images separately, requiring an acquisition time of typically ten minutes or more. The known imaging protocols use different image acquisition parameters like spatial resolution and slice location between perfusion-weighted and diffusion-weighted MR images, requiring a specially trained technician to manually align and overlay the images in a process which may take up to an hour. A system according to invention principally addresses the need to minimize time between diagnosis and intervention in ischemic stroke and associated problems.